The present invention generally relates to composites and more specifically relates to composites useful as fence components, decking components and the like, and methods for producing same.
Traditionally, fences and decks have been made of components fashioned from solid wood. Wood fences and decks are often considered more aesthetically appealing than those made of metal or cement, for example, wire fences or cement block walls or decks. However, construction of a wood fence or a wood deck is labor intensive. Solid wood components are heavy and cumbersome. In addition, maintenance of a wood fence or deck is expensive. After a period of time, solid wood fence and deck components will naturally begin to break down from weather exposure and pest infestations. It is known that this deterioration can be tempered by treating the fence or deck with widely available weather resistant coatings, paints, varnishes, finishes and the like. Unfortunately however, it is often only a matter of time before such treated fences or decks deteriorate requiring partial or complete replacement. Many solid wood materials that are suitable for fencing or decking are costly. In addition, because of natural variations in wood, replacement of individual components may result in an inconsistent, uneven appearance to the fence or deck.
Plastic fence components have been developed as alternatives or supplements to traditional, natural wood fences. For example, Robbins, III, U.S. Pat. No. 5,100,109 describes a method of constructing a fence by providing a flexible, plastic, rollable fence board that can be unrolled and fastened to spaced apart fence posts. The flexible fence board is made with height and width dimensions simulating a standard wooden board and with a length of 350 feet or more. According to this patent, the fence board is formed in a continuous extrusion process of a flexible thermoplastic material.
Collins U.S. Pat. No. 5,404,685, describes a wall or fence made in part of foamed polystyrene plastic components, more specifically, STYROFOAM(trademark) polystyrene plastic columns and panels. Construction of a fence in accordance with the Collins Patent requires multiple steps. For example, wall or fence stability is achieved by pouring a reinforcing filler, such as concrete, into a hollow of the polystyrene plastic columns after the columns have been secured to the ground. A hardened outer surface of the fence is achieved by applying an exterior finish, such as stucco or special exterior paint, to the fence or wall after the fence has been constructed.
There still remains a need in the market today for inexpensive, lightweight fencing and decking components and fence and deck systems that are sturdy, weather resistant, lightweight, and aesthetically appealing, and easy to manufacture using simple manufacturing techniques.
New composites, for example, useful in fence and deck systems and fence and decking components, such as rails, fence posts, fence slats, decking planks and the like, as well as methods for producing same have been discovered. The composites are easy to manufacture in a variety of configurations using relatively inexpensive materials. In addition, the composites are sturdy, lightweight and have excellent weatherability properties. In addition, the composites have many of the desirable properties of natural wood fences and decks. For example, the composites, in the form of fence and deck systems or fence and decking components, of the invention can be made to have a wood-like look and texture. However, unlike solid wood fences and decks, the composites of the present invention preferably are highly resistant to effects of weathering.
In a broad aspect of the invention, a layered composite is provided, which can be formed, for example, as a fence component or as a decking component.
The present composites, in general, comprise an outer layer comprising present composites a first polymeric material; a core layer, circumscribed by the outer layer and comprising a second polymeric material; and an inner layer, circumscribed by the core layer and comprising a third polymeric material, wherein the inner layer defines a hollow space. Preferably, the composites of the present invention are in the form of a member having a length defined along a longitudinal axis of the member. The hollow space preferably extends along substantially the entire length of the member. The core layer preferably is substantially completely circumscribed by the outer layer along substantially the entire length of the member and/or the inner layer preferably is substantially completely circumscribed by the core layer along substantially the entire length of the member. The member may have any suitable axial cross-section, such as circular, rectangular, oval, an irregularly shaped cross-section and the like. In one useful embodiment, the member has a substantially rectangular, for example, an elongated rectangular or square, axial cross-section, that is perpendicular to the length or longitudinal axis of the member.
In one especially advantageous embodiment of the invention, the composite is structured in the form of a fence building component or a fence component, for example, the composite may be in the form of a fence post or a fence rail or the like. Moreover, in accordance with the present invention, a fencing system is provided including a plurality of fence components, for example, a plurality of fence posts and a plurality of fence rails, wherein each of the fence components, e.g., each of the fence posts and fence rails, comprise a composite described herein.
In another useful embodiment, the composite is structured in the form of a deck building component or a decking component, for example, the composite may be in the form of a decking plank or the like. A deck system or decking system is provided in accordance with the present invention including a plurality of decking components, for example, a plurality of decking planks, wherein each of the decking components, e.g., each of the decking planks, comprise a composite described herein.
Each one of the first, second and third polymeric materials of the composite layers preferably comprises a thermoplastic polymeric material. In one embodiment of the invention, at least two of the first, second and third polymeric materials have different chemical compositions.
Preferably, the outer layer is made of a weatherable, thermoplastic polymeric material. The outer layer advantageously is substantially solid. As used herein, the term xe2x80x9cweatherablexe2x80x9d refers to the ability or property of a material to effectively withstand the conditions of an out-of-doors environment for a long period of time, for example, at least about five years and preferably at least about seven years or longer. Specific examples of polymers which can be used as the outer layer include, without limitation, polyvinylchloride, acrylonitrile/styrene/acrylic polymeric materials, and the like and mixtures or combinations thereof.
Preferably, the second material comprises a solid thermoplastic polymeric material or a thermoplastic polymeric material foam or combinations thereof, and an effective amount of a filler. Suitable polymeric materials for the core layer include, without limitation, polyvinylchloride, acrylonitrile/styrene/acrylic polymeric materials, acrylonitrile/butadiene/styrene polymeric materials, and the like and mixtures or combinations thereof. Any suitable filler component may be present in any of the layers of the present composites. Such filler component or components preferably are effective to add bulk and/or strength and/or reinforcement and/or stability to the layer and/or composite. Examples of useful filler components include, without limitation, wood, mica, talc, calcium carbonate, graphite or carbon, for example, in the form of particles, such as fibers, and the like and mixtures thereof. A filler component is particularly advantageous in the core layer, while the inner layer and/or outer layer preferably and substantially free of filler component. Preferably, the filler component of the core layer material comprises a wood component such as, but not limited to, wood particles, for example, wood shavings, wood chips, wood flour and the like and mixtures thereof. This use of a wood component advantageously provides an effective filler without unduly increasing the weight or cost of the composite.
The inner layer is circumscribed by the core layer and defines or bounds the hollow space of the composite. The inner layer can be made of a thermoplastic material which need not be weatherable, but preferably is effectively impact resistant. The inner layer is preferably substantially solid. Examples of materials that are suitable as the third polymeric material include, without limitation, polyvinylchloride, acrylonitrile/butadiene/styrene polymeric materials and the like and mixtures or combinations thereof.
Advantageously, the composites in accordance with the invention can be produced using a single coextrusion process using a suitable feedblock, pipehead and forming die assembly. The methods, in accordance with the present invention, for producing such composites comprise providing the desired materials, in an extrudable state, for the outer layer, the core layer and the inner layer, and passing the materials, by means of or through, three coextruders, into a feedblock/pipehead assembly to produce a material form having a radially layered, annular cross-section, for example, a substantially circular cylindrical axial cross-section. This material form is passed through a shaper die and is reconfigured thereby to produce or form a hollow, layered composite having a desired cross-section, for example, a square, elongated rectangle or other desired cross-section shape. Composites can be formed, e.g. cut, into different lengths and configurations to be useful as fence components, for example, rails and posts.
Any and all features described herein and combinations of such features are included within the scope of the present invention provided that the features of any such combination are not mutually inconsistent.
These and other features, aspects and advantages of the present invention will become apparent hereinafter, particularly when considered in conjunction with the following claims and detailed description in which like parts bear like reference numerals.